very high precision mechanical apparatus designed to pull (with rotation) single-crystal from the melt during CZ crystal growth process.

Czochralski crystal growth, CZ

process of obtaining single-crystal solids; the most common method for obtaining large diameter semiconductor wafers (e.g. 300 mm Si wafers); single crystal material is pulled out of the melt in which single-crystal seed is immersed and then slowly withdrawn; desired conductivity type and doping level is accomplished by adding dopants to the melt.